1. Field of the Invention
The present invention relates to an air cleaner for filtering an air taken inside an internal combustion engine of a vehicle.
2. Related Art
There is known an air cleaner of this kind in which an air cleaner case is arranged on the way of an intake duct arrangement of an internal combustion engine of a vehicle so that a filter element is detachably mounted in the case even at a time when the internal combustion engine is driven. For example, Japanese Patent Laid-open (KOKAI) Publication No. 122417/1997 discloses, such as shown in FIG. 18, an air cleaner having a case 1 through which air passes, and the case 1 is formed, at its side wall 1a, with an opening 2, into which a filter unit 3 is detachably mounted. The filter unit 3 is composed of two parts, that is, a filter element 4 and a holder 5 to which the filter element 4 is fitted.
The holder 5 comprises a lid member 5a closing the opening 2 formed on the case 1 and a holder frame 5b having a projection (protrusion) 6 formed at its lower end portion as viewed in FIG. 18, and the filter element 4 is accommodated in this holder frame 5b. On the other hand, the case 1 is formed with a groove 1b to be engageable with the projection 6 of the holder 5. That is, the filter unit 3 is inserted into the case 1 through the opening 2 and the projection 6 is then fitted to the groove 1b. The filter element 4 is provided with a packing 7 for sealing, and when the filter element 3 is rotated about the projection 6 as being a fulcrum, the packing 7 of the filter element 4 contacts an abutment surface 1c of the case, thus sealing a portion between the case 1 and the filter element 4.
In the air cleaner disclosed in the above prior art reference of Japanese Patent Laid-open Publication No. 122417/1997, as the filter unit 3 is rotated about the projection 6 as the fulcrum for rotation, a force of the packing 7 pushing the abutment surface 1c of the case 1 differs in accordance with a distance from the fulcrum, and therefore, even sealing performance cannot be achieved between the case 1 and the filter element 4. Furthermore, a packing may be disposed to the lower surface of the lid member 5a of the holder 5 for preventing water from invading inside the case 1. In such case, however, when the filter element 3 is inserted and rotated repeatedly, there may cause a case of peeling off the packing, thus being inconvenient.
The present invention was therefore conceived to substantially eliminate the defects or inconveniences encountered in the prior art mentioned above and provide an air cleaner in which two parts of a filter element and a holder are inserted and assembled detachably to a case of the air cleaner while maintaining a desirable sealing performance between the case and the filter element.
This and other objects can be achieved according to the present invention by providing an air cleaner which comprises:
a filter element, for filtrating air, including a frame structure, a filtrating member disposed in the frame structure, a flanged portion protruding from the outside of the frame structure and a seal portion;
a case provided with an air passage through which air passes and an opening through which the filter element is inserted into the case and having an abutment surface around the air passage to which the seal portion of the filter element contacts, the case being further provided with a guide portion for guiding the flanged portion of the filter element when inserted into the case through the opening and positioning the filter element in the air flow direction with respect to the case; and
a holder provided with a lid portion closing the opening of the case when fitted to the case and a wedged portion to be inserted between the case and the filter element,
wherein the filter element is first inserted into the case through the opening thereof and the holder is thereafter fitted into the case through the opening to thereby contact the seal portion of the filter element to the abutment surface of the case.
According to this structure, the filter element is first inserted into the case and then positioned, and thereafter, the holder is fitted into the case so as to contact the seal portion of the filter element to the abutment surface of the case, thus maintaining a good sealing performance.
Furthermore, in a preferred embodiment of the present invention, the guide portion is provided with a stepped portion formed on the opening of the case so as to surround the flanged portion of the filter element, the stepped portion extending in a filter element inserting direction from the opening towards an interior of the case.
The opening has a rectangular shape and the guide portion may comprise a plurality of ribs arranged inside the case along a filter element inserting direction. Other positioning ribs may be adapted to position the filter element, when inserted into the case through the opening, in the filter element inserting direction and to prevent an entire length of one side of the frame of the filter element from contacting to the case.
The frame structure of the filter element is formed with an inclination surface inclining with respect to the seal portion so as to be apart from the seal portion towards the inside of the case from the opening thereof, the case is formed with a holder guide surface to be parallel to the abutment surface of the case, the wedge portion of the holder is formed with an inclination surface inclining with respect to the holder guide surface so as to approach the holder guide surface towards the inside of the case from the opening, and the seal portion of the filter element abuts against the abutment surface of the case by contact of the inclination surface of the wedge portion of the holder with the inclination surface of the frame structure of the filter element.
Furthermore, the frame structure of the filter element may be formed with an end surface in parallel to the seal portion of the filter element, the case is formed with a holder guide surface inclining with respect to the abutment surface so as to approach the abutment surface towards the inside of the case from the opening thereof, the wedge portion of the holder is formed with an inclination surface inclining with respect to the abutment surface of the case so as to approach the abutment surface towards the inside of the case from the opening, and the seal portion of the filter element abuts against the abutment surface of the case by contact of the inclination surface of the wedge portion of the holder with the holder guide surface of the case.
The case will be composed of two case half parts, each in shape of an opened box, which can be joined together to form the case, the opening being formed at the joining portion and the case half parts being provided with air flow-in port and air flow-out port, respectively, so that air flows in a direction substantially normal to the filter element insertion direction. The abutment surface is formed on an opened end surface of one of these two half case parts in a flanged frame shape.
The wedge portion of the holder comprises a pair of wedge sections and a plate member connecting edge portions of the paired wedge sections.
According to these preferred embodiments, the location of the positioning ribs will make possible the easy positioning of the filter element and prevent the contacting of the entire length of the side of the frame structure of the filter element to thereby realize a uniform contacting of the seal portion of the filter element to the abutment surface of the case.
The formation of the inclination surfaces on the frame structure of the filter element and the wedge portion of the holder makes it possible to easily contact the seal portion of the filter element with the abutment surface of the case by fitting the holder into the case.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.